The "Everworld" series by K.A. Applegate is a young adult fantasy saga that explores the adventures of a group of teenagers who find themselves in a parallel universe where mythology and reality intertwine. This universe, known as Everworld, is a place where gods and mythical creatures from various pantheons coexist, and the teens must navigate this dangerous and unpredictable world while trying to find a way back home. Throughout the series, the characters confront personal fears, form alliances with mythical beings, and face off against powerful gods, all while dealing with the complexities of their own identities and relationships in a land that challenges their understanding of reality and fantasy.